The Eagles announced Friday that Pro Bowl left tackle Jason Peters ruptured his right Achilles' tendon Tuesday while working out in Texas.

The team said Peters will undergo surgery this coming Tuesday, quite possibly ending his 2012 season before it began, though no one with the Eagles is about to say that. Since Peters was hurt in the offseason, he could go on the physically unable to perform list instead of injured reserve, meaning he could start practicing with the team again six weeks into the season, if he were ready. We don't know how complete the tear was, but Achilles' tears generally require at least a sixth-month recovery for professional athletes, and it might take as long as a year for a player to perform at his customary skill level. Some players, particularly older players, never quite get back the agility they had before the injury. Peters turned 30 in January.

"We don't know when he will return to the field and we will not speculate on a timeline," Eagles coach Andy Reid said in a statement. "We are just going to let the surgical process and the rehabilitation process play itself out."

This is a stunning development for a team that had moved to solidify an improving offensive line, signing right tackle Todd Herremans and left guard Evan Mathis to long-term contracts. The Birds were looking forward to having a cohesive O-line, with a year under Howard Mudd's system behind it, that would be a strong suit as they try to get back into the playoffs.

Center Jason Kelce pointed out Friday that the team was 5-1 with all of its starting o-line members intact last season.

"We thought we were going to have some cohesion going on, but thus is football," Kelce said. "There's a lot of different things they can do. Howard (Mudd, the o-line coach) is coming back in next week. I'm sure he and Howie (Roseman, the general manager) will sit down and figure out what they need to do."

Reid said: "Howie and I will sort out the roster situation for the offensive line. We are glad to have King (Dunlap) back as part of our offensive line and we will continue to scan the free-agent market, also knowing the draft is less than a month away."

The team hurriedly signed sub tackle Dunlap to a one-year deal Friday, but Dunlap would be a stretch as a long-term replacement for one of the top left tackles in football. As Kelce noted, though Dunlap played well when pressed into action last season, he tended to get hurt every time he played.

Suddenly, a team that wasn't expected to draft an O-lineman in the first several rounds next month must consider using its first pick, 15th overall, on someone who might have to step in at left tackle as a rookie.

There are no difference-making left tackles available now in free agency, other than maybe Buffalo's Demetrious Bell, who would probably command a longterm investment to solve a short-term problem. (Of course, that's what drafting a tackle in the first round would do, as well.) Herremans filled in for Peters in a game against the Redskins last Oct. 16 and played well. The Eagles could move Herremans again (remember, this time last year he was the longtime left guard), and either play Dunlap on the right side or sign a right tackle free agent such as Kareem McKenzie from the Giants.

Kelce said that since quarterback Michael Vick is lefthanded, he wonders about the wisdom of moving Herremans away from the QB's blindside. But it's also true that the most dominant pass rushers often line up opposite the left tackle; Herremans played LT against the Redskins, instead of a sub doing it, because the Birds were concerned about Brian Orakpo on that side, more than they were about Vick's blindside.

Whatever happens, it's hard to believe the Eagles will have as good an o-line as they thought they might have before this happened.

"In my opinion, Jason was the best left tackle in the NFL last year," Kelce said.